if you spell shield lucian's piercing light and throw your q + w at him, you will win every trade. Just keep in mind, that you can't always use your shield for lucian's q because their support will take advantage of it.

Sivir has very high mobility, and is versatile in chasing, engaging and disengaging. While dueling sivir and when you are winning, sivir is sure to use her ult to run. You can use lucian to steal a Bike while drinking Kool Aid to chase after her.